Race-ethnic differences in adipokine levels: the Study of Women's Health Across the Nation (SWAN)

Are adipokines related to COVID-19 and its severity? A systematic review and meta-analysis

Introduction

The relationship between several adipokines and COVID-19 severity has lately been evaluated, results being inconclusive. Therefore, we aimed to assess the association between adipokines in COVID-19 and its severity.

Methods

A search was performed in PubMed, Scopus, and Embase using predefined keywords. The Newcastle of Ottawa Scale (NOS) was used for the quality assessment of included studies. The main summary outcome was the mean difference (MD) in adipokine levels.

Results

A total of 8 studies involving 473 individuals were included. A significant MD in serum adiponectin levels was demonstrated in mild vs. severe COVID-19 patients (-5.734 [95% CI -11.215 - -0.252]), with no significant MD in mild vs. moderate (-7.117 [95% CI -19.546 - 5.313]), or moderate vs. severe COVID-19 (-1.846 [95% CI -4.516 - 0.824]). Moreover, no significant MD was found in adiponectin and leptin levels when comparing COVID-19 patients vs. controls (-12.675 [95% CI -36.159 - 10.808]) and (8.034 [95% CI -10.403 - 26.471]), respectively.

Conclusion

Adiponectin levels were significantly increased in patients with severe compared to mild COVID-19. However, no significant MD was found in adiponectin levels in mild vs. moderate and moderate vs. severe COVID-19 patients, nor in adiponectin and leptin levels in COVID-19 patients vs. controls.

Association between bone health and dynapenic obesity in postmenopausal women

AIM

The combination of dynapenia (age-related muscle weakness) and obesity is referred to as dynapenic obesity. We examined the associations between dynapenic obesity and cortical bone thickness and trabecular bone density.

METHODS

The participants were 797 community-dwelling postmenopausal women (with an average age of 62.5 years) who were stratified into normopenia without obesity, dynapenia without obesity (dynapenia), normopenia with obesity (obesity) and dynapenia with obesity (dynapenia obesity) groups based on their grip strength and body fat percentage. Cortical bone thickness and trabecular bone density were measured using ultrasonic bone densitometry. The participants were further divided into those with low cortical bone thickness and low trabecular bone density. Logistic regression analysis was used to identify associated factors.

RESULTS

Individuals with dynapenia (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.16-2.68), obesity (OR 2.46, 95% CI 1.62-3.75) and dynapenic obesity (OR 4.07, 95% CI 2.44-6.79) all significantly increased the odds of low cortical bone thickness. Conversely, the odds of low trabecular bone density were significantly lower in the obesity group (OR 0.65, 95% CI 0.43-0.99) and dynapenic obesity group (OR 0.60, 95% CI 0.37-0.97).

CONCLUSIONS

Dynapenic obesity was found to be associated with cortical bone thinning that might compromise bone health. Postmenopausal women with dynapenic obesity might need to be closely monitored for preserving bone health. Geriatr Gerontol Int 2024; 24: 378-384.

Adipokines in atopic dermatitis: the link between obesity and atopic dermatitis

Atopic dermatitis (AD) is a chronic skin condition with intense pruritus, eczema, and dry skin. The recurrent intense pruritus and numerous complications in patients with AD can profoundly affect their quality of life. Obesity is one of its comorbidities that has been confirmed to be the hazard factor of AD and also worsen its severity. Nevertheless, the specific mechanisms that explain the connection between obesity and AD remain incompletely recognized. Recent studies have built hopes on various adipokines to explain this connection. Adipokines, which are disturbed by an obese state, may lead to immune system imbalances in people with AD and promote the development of the disease. This review focuses on the abnormal expression patterns of adipokines in patients with AD and their potential regulatory molecular mechanisms associated with AD. The connection between AD and obesity is elucidated through the involvement of adipokines. This conduces to the in-depth exploration of AD pathogenesis and provides a new perspective to develop therapeutic targets.

Relationship between leptin and white blood cells: a potential role in infection susceptibility and severity-the Olivetti Heart Study

A number of evidence showed an emerging role of leptin on immune system, involving inflammation, and innate and adaptive immunity. Few observational studies have evaluated the relationship between leptin and immunity, albeit with low statistical power and methodological differences. Therefore, the aim of this study was to evaluate the potential role of leptin on the immunity, expressed as white blood cells (WBC)-and its subpopulations, by comprehensive multivariate models in a sample of adult men. A cross-sectional evaluation of a general population comprised 939 subjects participating in the Olivetti Heart Study, with available leptin levels and WBC-and its subpopulations. WBC were significantly and positively associated with leptin, C-reactive protein and HOMA index (p < 0.05), but not with age and anthropometric indices (p > 0.05). The multivariate analysis confirmed the association between leptin and WBC, after accounting for main confounders (p < 0.05). Additional analysis on WBC subpopulations showed a positive and significant correlation between leptin and lymphocytes, monocytes and eosinophils (p < 0.05), but not with neutrophils and basophils (p > 0.05). After stratification by body weight, the positive and significant association between leptin and WBC-and its subpopulations-was found in excess body weight participants. The results of this study indicate a direct relationship between leptin levels and WBC-and its subpopulations-in excess body weight participants. These results support the hypothesis that leptin has modulatory functions on immunity and role in the pathophysiology of immune-related diseases, in particular in those associated with excess body weight.

The associations of adipokines with hypertension in youth with cardiometabolic risk and the mediation role of insulin resistance: The BCAMS study

The mechanisms link obesity and hypertension are not well understood. One possibility is the alterations in adipose-derived adipokines that modulate insulin resistance (IR) and cardiovascular homeostasis. We aimed to assess the associations between hypertension and four adipokine levels in Chinese youth, and to examine to what extent the associations are mediated by IR. We utilized cross-sectional data from the Beijing Children and Adolescents Metabolic Syndrome (BCAMS) Study Cohort (n = 559, mean age = 20.2 years). Plasma leptin, adiponectin, retinol binding protein 4 (RBP4) and fibroblast growth factor 21 (FGF21) levels were assayed. The relationships between adipokines and hypertension and the possible mediation effect of IR were evaluated. Youth with hypertension have lower adiponectin and higher leptin, FGF21 (all P < 0.001) and RBP4 levels (p = 0.06) compared to their counterparts. Moreover, the co-existence of these two or more adipokine abnormalities in youth leads to a 9-fold increased risk for hypertension (OR: 9.19; 95% CI, 4.01-21.08) compared with these without abnormalities. However, in the fully adjusted and BMI-adjusted analyses, only FGF21 was a significant predictor of hypertension (OR: 2.12; 95% CI, 1.34-3.36). Mediation analysis revealed that the associations between leptin, adiponectin, RBP4 and hypertension are totally mediated by IR (proportion: 63.9%, 65.4%, and 31.6%, respectively), while BMI and IR partly mediated the association between FGF21 and hypertension (proportion: 30.6%, 21.2%). Our findings suggest that dysregulation of adipokines might result in hypertension in youth. Leptin, adiponectin and RBP4 may exert their functions in hypertension through adiposity-related IR, whereas FGF21 might be used as an independent marker of hypertension in youth.

Association between vasomotor symptom frequency and weight gain in the Study of Women's Health Across the Nation

OBJECTIVE

The menopause transition is associated with weight gain in women. We examined whether changes in vasomotor symptom (VMS) frequency precede weight changes.

METHODS

This longitudinal retrospective analysis included data from the multisite, multiethnic Study of Women's Health Across the Nation. Women in premenopause or perimenopause aged 42 to 52 years at baseline self-reported VMS frequency (hot flashes/night sweats) and sleep problems at up to 10 annual visits. Menopause status, weight, body mass index, and waist circumference were compared across visits. The primary objective was to measure the association between VMS frequency and weight gain using a lagged approach with first-difference regression models. Secondary objectives were to statistically quantify mediation by sleep problems and moderation by menopause status and explore the association between cumulative, 10-year VMS exposure and long-term weight gain.

RESULTS

The primary analysis sample included 2,361 participants (12,030 visits; 1995-2008). Increased VMS frequency across visits was associated with subsequently increased weight (0.24 kg), body mass index (0.08 kg/m 2 ), and waist circumference (0.20 cm). Cumulative exposure to a high frequency of VMS (≥6 d/2 wk) over 10 consecutive annual visits was associated with increases in weight measures, including a 3.0-cm increase in waist circumference. Contemporaneous sleep problems mediated no more than 27% of waist circumference increases. Menopause status was not a consistent moderator.

CONCLUSIONS

This study demonstrates that increases in VMS, onset of a high frequency of VMS, and persistent VMS symptoms over time may precede weight gain in women.

Feeding a High-Fat Diet for a Limited Duration Increases Cancer Incidence in a Breast Cancer Model

High-fat intake by young Asian women impacts the risk of breast cancer. Understanding the underlying molecular mechanisms may be essential for disease prevention in Asia as well as globally. We aimed to examine the effects of corn oil- and animal fat-based high-fat diets (32.9 and 31.4%, respectively, of fat energy ratio as compared to 12.3% in the standard diet) on mammary carcinogenesis and alterations in gene expression and epigenetic statuses in the mammary gland during the growth stages in a rat model. An increased incidence of carcinomas was observed after the cessation of high-fat feeding. In addition, rapid tumor growth and elevations in Celsr2 expression, which may be a result of DNA hypomethylation patterns in the 3' untranslated region of the gene were noted in the animal fat group. In the human breast carcinoma cell line MCF7, a marginal decrease in cell viability was observed following the knockdown of Celsr2, suggesting that the animal fat-associated risk of cancer is partly due to the deregulation of mammary cell proliferation via non-metabolic gene functions. The present results will contribute to the development of strategies for controlling the food-associated risk of breast cancer, particularly in younger age groups.

The relationship between adipokine levels and bone mass-A systematic review

INTRODUCTION

Adipose tissue is the source of a broad array of signalling molecules (adipokines), which mediate interorgan communication and regulate metabolic homeostasis. Alterations in adipokine levels have been causally implicated in various metabolic disorders, including changes in bone mass. Osteoporosis is the commonest progressive metabolic bone disease, characterized by elevated risk of fragility fractures as a result of a reduced bone mass and microarchitectural deterioration. The effects of different adipokines on bone mass have been studied in an attempt to identify novel modulators of bone mass or diagnostic biomarkers of osteoporosis.

METHODS

In this review, we sought to aggregate and assess evidence from independent studies that quantify specific adipokines and their effect on bone mineral density (BMD).

RESULTS

A literature search identified 57 articles that explored associations between different adipokines and BMD. Adiponectin and leptin were the most frequently studied adipokines, with most studies demonstrating that adiponectin levels are associated with decreased BMD at the lumbar spine and femoral neck. Conversely, leptin levels are associated with increased BMD at these sites. However, extensive heterogeneity with regards to sample size, characteristics of study subjects, ethnicity, as well as direction and magnitude of effect at specific skeletal anatomical sites was identified. The broad degree of conflicting findings reported in this study can be attributed several factors. These include differences in study design and ascertainment criteria, the analytic challenges of quantifying specific adipokines and their isoforms, pre-analytical variables (in particular patient preparation) and confounding effects of co-existing disease.

CONCLUSIONS

This review highlights the biological relevance of adipokines in bone metabolism and reinforces the need for longitudinal research to elucidate the causal relationship of adipokines on bone mass.

Genetic pleiotropy underpinning adiposity and inflammation in self-identified Hispanic/Latino populations

BACKGROUND

Concurrent variation in adiposity and inflammation suggests potential shared functional pathways and pleiotropic disease underpinning. Yet, exploration of pleiotropy in the context of adiposity-inflammation has been scarce, and none has included self-identified Hispanic/Latino populations. Given the high level of ancestral diversity in Hispanic American population, genetic studies may reveal variants that are infrequent/monomorphic in more homogeneous populations.

METHODS

Using multi-trait Adaptive Sum of Powered Score (aSPU) method, we examined individual and shared genetic effects underlying inflammatory (CRP) and adiposity-related traits (Body Mass Index [BMI]), and central adiposity (Waist to Hip Ratio [WHR]) in HLA participating in the Population Architecture Using Genomics and Epidemiology (PAGE) cohort (N = 35,871) with replication of effects in the Cameron County Hispanic Cohort (CCHC) which consists of Mexican American individuals.

RESULTS

Of the > 16 million SNPs tested, variants representing 7 independent loci were found to illustrate significant association with multiple traits. Two out of 7 variants were replicated at statistically significant level in multi-trait analyses in CCHC. The lead variant on APOE (rs439401) and rs11208712 were found to harbor multi-trait associations with adiposity and inflammation.

CONCLUSIONS

Results from this study demonstrate the importance of considering pleiotropy for improving our understanding of the etiology of the various metabolic pathways that regulate cardiovascular disease development.

The Interplay of Race/Ethnicity and Obesity on the Incidence of Venous Thromboembolism

INTRODUCTION

Factors predisposing asymptomatic individuals within the community to venous thromboembolism are not fully understood. This study characterizes the incidence and determinants of venous thromboembolism among the Multiethnic Study of Atherosclerosis cohort with a focus on race/ethnicity and obesity.

METHODS

This study (analyzed in 2020-2021) used the Multiethnic Study of Atherosclerosis cohort (2000-2017), which included participants with diverse ethnic/racial backgrounds aged 45-84 years without cardiovascular disease at baseline. The primary endpoint was time to diagnosis of venous thromboembolism defined using International Classification of Diseases codes (415, 451, 453, 126, 180, and 182). Multivariable-adjusted hazard ratios of the predictors of venous thromboembolism were calculated with a focus on the interaction between obesity and race/ethnicity categories.

RESULTS

Over a median follow-up period of 14 years, 233 individuals developed venous thromboembolism. Incidence rates (per 1,000 person-years) varied across racial/ethnic groups with the highest incidence among Black (4.02) followed by White (2.98), Hispanic (2.08), and Chinese (0.79) participants. There was a stepwise increase in the incidence rate of venous thromboembolism with increasing BMI regardless of race/ethnicity: normal (1.95), overweight (2.52), obese (3.63), and morbidly obese (4.55). The association between BMI and venous thromboembolism was strongest among non-White women with the highest incidence rate for obese (4.8) compared with non-obese (1.6). The interaction among obesity, gender, and race was statistically significant (p=0.01) in non-White obese women. Risk of venous thromboembolism increased with age for all race/ethnicities.

CONCLUSIONS

This study finds that obesity may confer an increased risk for venous thromboembolism among non-White women compared with other groups-White men, White women, and non-White men.

Race-specific associations of urinary phenols and parabens with adipokines in midlife women: The Study of Women's Health Across the Nation (SWAN)

Adipokines, cytokines secreted by adipose tissue, may contribute to obesity-related metabolic disease. The role of environmental phenols and parabens in racial difference in metabolic disease burden has been suggested, but there is limited evidence. We examined the cross-sectional associations of urinary phenols and parabens with adipokines and effect modification by race. Urinary concentrations of 6 phenols (bisphenol-A, bisphenol-F, 2,4-diclorophenol, 2,5-diclorophenol, triclosan, benzophenone-3) and 4 parabens (methyl-paraben, ethyl-paraben, propyl-paraben, butyl-paraben) were measured in 2002-2003 among 1200 women (mean age = 52.6) enrolled in the Study of Women's Health Across the Nation Multi-Pollutant Study. Serum adipokines included adiponectin, high molecular weight (HMW)-adiponectin, leptin, soluble leptin receptor (sOB-R). Linear regression models were used to estimate the adjusted percentage change in adipokines per inter-quantile range (IQR) increase in standardized and log-transformed levels of individual urinary phenols and parabens. Bayesian kernel machine regression (BKMR) was used to evaluate the joint effect of urinary phenols and parabens as mixtures. Participants included white (52.5%), black (19.3%), and Asian (28.1%) women. Urinary 2,4-dichlorophenol was associated with 6.02% (95% CI: 1.20%, 10.83%) higher HMW-adiponectin and urinary bisphenol-F was associated with 2.60% (0.48%, 4.71%) higher sOB-R. Urinary methyl-paraben was associated with lower leptin in all women but this association differed by race: 8.58% (-13.99%, -3.18%) lower leptin in white women but 11.68% (3.52%, 19.84%) higher leptin in black women (P interaction = 0.001). No significant associations were observed in Asian women. Additionally, we observed a significant positive overall effect of urinary phenols and parabens mixtures in relation to leptin levels in black, but not in white or Asian women. Urinary bisphenol-F, 2,4-dichlorophenol and methyl-paraben may be associated with favorable profiles of adipokines, but methyl-paraben, widely used in hair and personal care products, was associated with unfavorable leptin levels in black women. Future studies are needed to confirm this racial difference.

Disparities in Reproductive Aging and Midlife Health between Black and White women: The Study of Women's Health Across the Nation (SWAN)

This paper reviews differences in the experience of the menopause transition and midlife health outcomes between Black and White women who participated in the Study of Women's Health Across the Nation (SWAN), a 25-year, longitudinal, multi-racial/ethnic cohort study. We identify health disparities, i.e., instances in which Black women's outcomes are less favorable than those of White women, and consider whether structural racism may underlie these disparities. Although SWAN did not explicitly assess structural racism, Black women in SWAN grew up during the Jim Crow era in the United States, during which time racism was legally sanctioned. We consider how we might gain insight into structural racism by examining proxy exposures such as socioeconomic characteristics, reports of everyday discrimination, and a range of life stressors, which likely reflect the longstanding, pervasive and persistent inequities that have roots in systemic racism in the US. Thus, this paper reviews the presence, magnitude, and longitudinal patterns of racial disparities observed in SWAN in six areas of women's health - menopause symptoms, sleep, mental health, health related quality of life, cardio-metabolic health, and physical function -and elucidates the contextual factors that are likely influencing these disparities. We review the strengths and weaknesses of SWAN's design and approach to analysis of racial disparities and use this as a springboard to offer recommendations for future cohort studies.

Genome-wide analyses of multiple obesity-related cytokines and hormones informs biology of cardiometabolic traits

BACKGROUND

A complex set of perturbations occur in cytokines and hormones in the etiopathogenesis of obesity and related cardiometabolic conditions such as type 2 diabetes (T2D). Evidence for the genetic regulation of these cytokines and hormones is limited, particularly in African-ancestry populations. In order to improve our understanding of the biology of cardiometabolic traits, we investigated the genetic architecture of a large panel of obesity- related cytokines and hormones among Africans with replication analyses in African Americans.

METHODS

We performed genome-wide association studies (GWAS) in 4432 continental Africans, enrolled from Ghana, Kenya, and Nigeria as part of the Africa America Diabetes Mellitus (AADM) study, for 13 obesity-related cytokines and hormones, including adipsin, glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), interleukin-1 receptor antagonist (IL1-RA), interleukin-6 (IL-6), interleukin-10 (IL-10), leptin, plasminogen activator inhibitor-1 (PAI-1), resistin, visfatin, insulin, glucagon, and ghrelin. Exact and local replication analyses were conducted in African Americans (n = 7990). The effects of sex, body mass index (BMI), and T2D on results were investigated through stratified analyses.

RESULTS

GWAS identified 39 significant (P value < 5 × 10-8) loci across all 13 traits. Notably, 14 loci were African-ancestry specific. In this first GWAS for adipsin and ghrelin, we detected 13 and 4 genome-wide significant loci respectively. Stratified analyses by sex, BMI, and T2D showed a strong effect of these variables on detected loci. Eight novel loci were successfully replicated: adipsin (3), GIP (1), GLP-1 (1), and insulin (3). Annotation of these loci revealed promising links between these adipocytokines and cardiometabolic outcomes as illustrated by rs201751833 for adipsin and blood pressure and locus rs759790 for insulin level and T2D in lean individuals.

CONCLUSIONS

Our study identified genetic variants underlying variation in multiple adipocytokines, including the first loci for adipsin and ghrelin. We identified population differences in variants associated with adipocytokines and highlight the importance of stratification for discovery of loci. The high number of African-specific loci detected emphasizes the need for GWAS in African-ancestry populations, as these loci could not have been detected in other populations. Overall, our work contributes to the understanding of the biology linking adipocytokines to cardiometabolic traits.

Circulating levels of FAM19A5 are inversely associated with subclinical atherosclerosis in non-alcoholic fatty liver disease

BACKGROUND

Family with sequence similarity 19 (chemokine (C-C motif)-like) member A5 (FAM19A5) is a newly identified adipokine. There is a limited number of studies linking FAM19A5 to metabolic disorders. In the current study, we aimed to explore if FAM19A5 is associated with nonalcoholic fatty liver disease (NAFLD). We also sought to determine the possibility of FAM19A5 association with subclinical atherosclerosis in NAFLD patients.

METHODS

A total of 69 subjects including 37 NAFLD and 32 control subjects were included in this cross-sectional study. Plasma concentration of FAM19A5 was measured with the ELISA method. Carotid artery intima-media thickness (cIMT) was assessed by the ultrasonography.

RESULTS

Plasma concentration of FAM19A5 in patients with NAFLD was significantly lower in NAFLD patients than controls. Moreover, we observed significant negative correlations between plasma level of FAM19A5 and body mass index (BMI), visceral fat, alanine amino transferase (ALT), aspartate amino transferase (AST), liver stiffness (LS), and cIMT. Following stepwise multiple linear regression analysis, ALT and cIMT were the only determinants of FAM19A5 level.

CONCLUSIONS

This is the first report to describe association of circulating FAM19A5 levels with NAFLD. Our findings provide further evidence showing relation of FAM19A5 with the risk of atherosclerosis. However, more studies are necessary to unravel the contribution of lower FAM19A5 levels to the NAFLD pathogenesis and the higher risk of atherosclerosis in these patients.

Correlation between plasma ZAG and adiponectin in older adults: gender modification and frailty specificity

Background

Adiponectin and zinc alpha2-glycoprotein (ZAG) are associated with frailty. This study aims to further examine the association of adiponectin with ZAG.

Methods

Outpatients aged 65 years or older with chronic disease followed up in a hospital-based program were recruited for a comprehensive geriatric assessment. We excluded outpatients who were bedridden, residing in a nursing home, with expected life expectancy less than 6 months, or with severe hearing or communication impairment. Plasma ZAG and adiponectin levels were measured. Association between plasma ZAG and adiponectin levels was analyzed by univariate and multivariable linear regression analyses.

Results

A total of 189 older adults were enrolled (91 men and 98 women, mean age: 77.2 ± 6.1 years). Log-transformed plasma ZAG level was 1.82 ± 0.11 μg/mL, and it was significantly higher in men than that in women (1.85 ± 0.12 vs 1.79 ± 0.10 μg/mL, P = .0006). Log-transformed plasma adiponectin level was 1.00 ± 0.26 μg/mL, and there was no significant gender difference (P = .195). Overall, plasma ZAG level positively correlated with plasma adiponectin level in the multivariable linear regression analysis (P = .0085). The gender-specific significance, however, was less clear: this relationship was significant in men (P = .0049) but not in women (P = .2072). To be more specific by frailty phenotype components, plasma adiponectin was positively correlated with weight loss (P = .0454) and weakness (P = .0451).

Conclusions

Both of ZAG and adiponectin may be potential frailty biomarkers. Plasma ZAG is an independent factor of plasma adiponectin, especially in older male adults.

Plasma Adiponectin and Blood Pressure Progression in African Americans: The Jackson Heart Study

BACKGROUND

Little is known on the association of plasma adiponectin with blood pressure (BP) changes in African Americans (AAs). We evaluated the associations between plasma adiponectin and BP progression among AAs.

METHODS

We analyzed data from 1,184 participants without hypertension at baseline (2000-2004) with ≥1 follow-up visits in the Jackson Heart Study. We used robust Poisson regression to generate risk ratios (RRs) for BP progression (an increase by ≥1 BP stage) and incident hypertension.

RESULTS

Over a median of 7 years, 71% progressed to higher BP stage and 65% developed hypertension. We found evidence of interaction by sex (P-interaction = 0.088). Compared with those in the lowest quartile (Q1), male participants in the highest adiponectin quartile (Q4) had reduced risks of BP progression (RR 0.76 [95% confidence interval, CI, 0.60-0.96]) and incident hypertension (RR 0.74 [95% CI 0.56-0.97]). After accounting for body mass index, this relation persisted among obese men (RR for the highest [vs. lowest] adiponectin quartile: 0.59 [95% CI 0.36-0.97] for incident hypertension, and 0.69 [95% CI 0.45-1.06] for BP progression). Among women, adiponectin was not associated with BP outcomes (RR [95% CI] for Q4 vs. Q1: 1.03 [0.86-1.23] and 1.01 [0.83-1.23] for BP progression and incident hypertension, respectively). Our findings were consistent across both the American College of Cardiology (ACC)/American Heart Association (AHA) and Seventh Joint National Committee (JNC-7) BP categories.

CONCLUSIONS

In a large, community-based sample of AAs, higher adiponectin concentrations were associated with lower risks of BP progression and incident hypertension in men, but no significant association was observed in women.

Obesity in early onset breast cancer in African American patients

Obesity is a modifiable risk factor in breast cancer patients and is predictive of disease outcomes in early-onset breast cancer survivors. The purpose of this review is to summarize the current evidence in the association between early-onset breast cancer and obesity, specifically in African-American women. Reviewing the molecular mechanisms and social determinants of disease in this population can provide a foundation for future interventions in prevention, detection, and treatment aiming at improving outcomes for young breast cancer patients.

Associations of perfluoroalkyl and polyfluoroalkyl substances (PFAS) and PFAS mixtures with adipokines in midlife women

BACKGROUND

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) exposure have been associated with obesity and related comorbidities, possibly through disrupting signaling pathways of adipokines. Both leptin and adiponectin can modulate metabolic processes. However, the effects of PFAS on adipokines are not well understood.

OBJECTIVE

We determined if serum PFAS concentrations were associated with adipokine profiles in midlife women.

METHODS

We examined 1245 women aged 45-56 years from the Study of Women's Health Across the Nation. Concentrations of 11 PFAS were quantified in baseline serum samples collected in 1999-2000. Linear and branched perfluorooctane sulfonic acid isomers (n-PFOS and Sm-PFOS) and their sum (PFOS), linear perfluorooctanoic acid (n-PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), 2-(N-methyl-perfluorooctane sulfonamido) acetic acid (MeFOSAA), and 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid (EtFOSAA) with detection frequencies >60% were included in the analysis. Adipokines including leptin, soluble leptin receptor (sOB-R), free leptin index (FLI, the ratio of leptin to sOB-R), total and high molecular weight (HMW) adiponectin were assessed in 2002-2003. We utilized multivariable linear regressions and Bayesian kernel machine regression (BKMR) to assess individual and overall joint effects of PFAS on adipokines with adjustment for age, race/ethnicity, study site, education, smoking status, physical activity, menopausal status, and waist circumference.

RESULTS

A doubling of PFAS concentrations was associated with 7.8% (95% CI: 2.5%, 13.4%) higher FLI for PFOS, 9.4% (95% CI: 3.7%, 15.3%) for n-PFOA, 5.5% (95% CI: 2.2%, 9.0%) for EtFOSAA and 7.4% (95% CI: 2.8%, 12.2%) for MeFOSAA. Similar associations were found for leptin. Only EtFOSAA was associated with lower sOB-R concentrations (-1.4%, 95% CI: -2.7%, -0.1%). Results remained in women with overweight or obesity but not those with normal weight or underweight. No statistically significant associations were observed with total or HMW adiponectin, except for PFNA with total and HMW adiponectin observed in women with normal weight or underweight. In BKMR analysis, women with PFAS concentrations at the median and the 90th percentile had 30.9% (95% CI: 15.6%, 48.3%) and 52.1% (95% CI: 27.9%, 81.0%) higher FLI, respectively, compared with those with concentrations fixed at the 10th percentile.

CONCLUSION

Some PFAS may alter circulating levels of leptin. Understanding associations between PFAS and adipokines may help elucidate whether PFAS can influence obesity and metabolic disease.

Plasma Leptin and Blood Pressure Progression in Blacks: The Jackson Heart Study

[Figure: see text].

Adipokines and Subclinical Cardiovascular Disease in Post-Menopausal Women: Study of Women's Health Across the Nation

Background The menopausal transition is characterized by increased cardiovascular risk, weight gain, and increased adiposity for many women. The adipose-derived secretory proteins adiponectin and leptin are associated with insulin resistance, metabolic syndrome, and cardiovascular disease but their role in subclinical atherosclerotic disease is unclear. This cross-sectional study evaluated the associations of adiponectin and leptin with carotid artery intima-media thickness, adventitial diameter, presence of carotid plaques, and brachial-ankle pulse wave velocity (baPWV) in women aged 54 to 65 years. Methods and Results Participants were 1399 women from SWAN (Study of Women's Health Across the Nation), a community-based study of women transitioning through menopause. Carotid ultrasound and baPWV measures were obtained at SWAN follow-up visits 12 or 13, when 97% of participants were post-menopausal. Adipokines were assayed from serum specimens obtained concurrently at these visits. Linear and logistic regression models were used to evaluate adiponectin or leptin, both log-transformed attributable to skewness, in relationship to carotid artery intima-media thickness, adventitial diameter, baPWV, and presence of carotid plaque. Covariates included age, race, study site, smoking, alcohol use, obesity, cardiovascular disease risk factors, and menopausal status. Lower levels of adiponectin were related to greater carotid artery intima-media thickness, wider adventitial diameter, and faster baPWV; associations were attenuated after adjusting for cardiovascular disease risk factors. Higher levels of leptin were associated with greater carotid artery intima-media thickness and wider adventitial diameter in minimally and fully adjusted models, and contrary to expectation, with slower baPWV, particularly among women with diabetes mellitus or obesity. Conclusions Adiponectin and leptin are 2 important inflammatory pathways that may contribute to adverse subclinical cardiovascular disease risk profiles in women at midlife.

Role of Adiponectin Gene and Receptor Polymorphisms and Their mRNA Levels with Serum Adiponectin Level in Myocardial Infarction

Background and Aim

Genetic factors are vital participants in the development and progression of myocardial infarction (MI). Adiponectin has been assumed to have a protective role in MI and adiponectin receptors variants could be a determinant for atherosclerosis. We aimed to evaluate the prevalence of ADIPOQ (rs2241766) and ADIPOR2 (rs10773989) polymorphisms and their association with mRNA levels and circulatory adiponectin levels in patients with MI.

Subjects and Methods

A total of 220 participants were classified into two groups: group 1 included 120 patients with MI, and group 2 involved 100 healthy participants as controls. Genotyping of ADIPOQ (rs2241766) and ADIPOR2 (rs10773989) polymorphisms were analyzed using an allele discrimination assay with real-time PCR and their relative expression or mRNA levels were determined by real-time PCR. Serum adiponectin level was determined using an ELISA technique.

Results

The ADIPOQ rs2241766 GG genotype and G allele and the CC genotype and C allele of ADIPOR2 rs10773989 were significantly prevalent in patients with MI and associated with increased risk of MI. We detected a marked reduction in serum adiponectin, ADIPOQ and ADIPOR2 mRNA levels in patients than control. The GG genotype of ADIPOQ rs2241766 and the CC genotype of ADIPOR2 rs10773989 had the lowest levels of their mRNA and adiponectin level in both patients and controls.

Conclusion

Adiponectin gene and receptor variants are potentially related to MI risk; furthermore, their expressions were markedly depressed in MI which suggests their use as potential biomarkers for MI.

Association of plasma adiponectin with pulmonary hypertension, mortality and heart failure in African Americans: Jackson Heart Study

Background

Adiponectin is a polypeptide hormone related to obesity, and a known modulator of pulmonary vascular remodeling. Association between plasma adiponectin levels and pulmonary hypertension (PH) has not been studied in African Americans (AAs) who are disproportionately affected by obesity. The relationship between adiponectin and heart failure (HF) and mortality, outcomes associated with PH, is unclear.

Methods

We performed cross-sectional and longitudinal analysis to examine if there is an association between plasma adiponectin and PH and associated clinical outcomes, in participants of Jackson Heart Study (JHS). JHS is a prospective observational cohort study of heart disease in AAs from Jackson, Mississippi.

Results

Of the 3161 participants included in the study, mean age (SD) was 56.38 (12.61) years, 1028 were men (32.5%), and mean (SD) BMI was 31.42 (7.05) kg/m². Median (IQR) adiponectin was 4516.82 (2799.32–7065.85) ng/mL. After adjusting for potential confounders including BMI, higher adiponectin levels were associated with increased odds of PH (adjusted odds ratio per log increment in adiponectin, (1.81; 95% CI, 1.41–2.32). High adiponectin levels were also associated with associated HF admissions (adjusted hazard ratio [HR] per log increment in adiponectin, 1.63, 95% CI, 1.24–2.14) and mortality (adjusted HR per log increment in adiponectin, 1.20; 95% CI 1.02–1.41).

Conclusions

Elevated plasma adiponectin levels are associated with PH, HF admissions and mortality risk in AAs. High adiponectin levels may help identify an at-risk population that could be evaluated for targeted prevention and management strategies in future studies

Exercise augments the modulatory effects of vitamin E on pre-diabetes-induced aortopathy: a potential role of adiponectin

Background: We tested the hypothesis that vitamin E may protect against pre-diabetes-induced aortic injury (aortopathy), and exercise can augment the action of vitamin E.Material and methods: Rats were either fed with a high fat and fructose diet (HFD) (model group) or a standard laboratory chow (control group) for 15 weeks before being sacrificed. The three protective groups were treated with vitamin E (HFD + Vit E), swimming exercises (HFD + Ex), and vitamin E plus swimming exercises (HFD + VitE + Ex), respectively.Results: Aortopathy was developed in the model group as demonstrated by substantial tissue ultrastructural alterations, which were partially protected by vitamin E and effectively protected with vitamin E plus swim exercise. Also, swimming exercises significantly (p < .05) increased the modulatory effects of vitamin E on dyslipidemia, insulin resistance, blood pressure, oxidative stress, inflammation, leptin, and adiponectin, except coagulation and thrombosis.Conclusions: Swim exercise augments the protective effects of vitamin E in a pre-diabetic animal model.

Influence of Genetic Ancestry on Human Serum Proteome

Disease risk varies significantly between ethnic groups, however, the clinical significance and implications of these observations are poorly understood. Investigating ethnic differences within the human proteome may shed light on the impact of ancestry on disease risk. We used admixture mapping to explore the impact of genetic ancestry on 237 cardiometabolic biomarkers in 2,216 Latin Americans within the Outcomes Reduction with an Initial Glargine Intervention (ORIGIN) study. We developed a variance component model in order to determine the proportion of variance explained by inter-ancestry differences, and we applied it to the biomarker panel. Multivariable linear regression was used to identify and localize genetic loci affecting biomarker variability between ethnicities. Variance component analysis revealed that 5% of biomarkers were significantly impacted by genetic admixture (p < 0.05/237), including C-peptide, apolipoprotein-E, and intercellular adhesion molecule 1. We also identified 46 regional associations across 40 different biomarkers (p < 1.13 × 10^-6). An independent analysis revealed that 34 of these 46 regions were associated at genome-wide significance (p < 5 × 10^-8) with their respective biomarker in either Europeans or Latin populations. Additional analyses revealed that an admixture mapping signal associated with increased C-peptide levels was also associated with an increase in diabetes risk (odds ratio [OR] = 6.07 per SD, 95% confidence interval [CI] 1.44 to 25.56, p = 0.01) and surrogate measures of insulin resistance. Our results demonstrate the impact of ancestry on biomarker levels, suggesting that some of the observed differences in disease prevalence have a biological basis, and that reference intervals for those biomarkers should be tailored to ancestry. Specifically, our results point to a strong role of ancestry in insulin resistance and diabetes risk.

Serum concentration of asprosin in new-onset type 2 diabetes

BACKGROUND

Asprosin, a newly identified adipokine, is pathologically increased in individuals with insulin resistance. However, the available evidence on the association of asprosin and type 2 diabetes mellitus (T2DM) status is still scarce. Therefore, this study aimed to determine the relationship between serum concentrations of asprosin and T2DM status.

METHODS

This observational study was performed based on 194 adults (97 newly diagnosed T2DM and 97 healthy individuals). Anthropometric and biochemical variables were determined in all participants. Serum concentrations of asprosin were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

In patients with T2DM, the serum concentrations of asprosin were significantly higher than the healthy controls (4.18 [IQR: 4.4] vs. 3.5 [IQR: 1.85], P < 0.001). The concentrations of asprosin were significantly correlated with body mass index (BMI) and fasting blood glucose (FBG) in healthy subjects and with BMI, FBG, hemoglobin A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), and quantitative insulin check index (QUICKI), triacylglycerol (TAG) and total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio in the T2DM group. In fully adjusted model, the odds ratio (OR) of T2DM with serum concentrations of asprosin was approximately 1.547 (95% CI 1.293-1.850, P < 0.001) compared to the control group. Multiple stepwise regression analysis indicated that FBG and HOMA-IR were independently associated with asprosin in T2DM.

CONCLUSION

Our findings indicated that serum concentrations of asprosin are increased in patients with T2DM. Also, asprosin is correlated with insulin resistance and TC/HDL-C ratio (atherosclerotic risk factor of cardiovascular diseases) in patients with T2DM.

Racial Disparity in the Sex Distribution, the Prevalence, and the Incidence of Dysplasia in Barrett's Esophagus

GOALS

Our aim was to study the prevalence of dysplasia and progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in African Americans (AA) with Barrett's esophagus (BE) and compare it with that of non-Hispanic white (NHW) controls.

BACKGROUND

BE, a precursor of EAC, is a disease of predominantly white men and is uncommon in AA. The prevalence of dysplasia and progression to HGD and EAC in AA patients with BE is not clearly known.

STUDY

All AA or NHW patients with confirmed BE, that is specialized intestinal metaplasia, seen between 2002 and 2013 at our institution were included. Variables such as age, gender, medication use, the body mass index, the date of endoscopy, the hiatal hernia size, the BE length, and histologic findings were noted. Progression to HGD/EAC was evaluated.

RESULTS

Fifty-two AA and 2394 NHW patients with BE were identified. There was a higher percentage of women in the AA cohort (46.2%) than in the NHW cohort (24.9%, P<0.001). Nondysplastic BE was more prevalent in AA than in NHW (80.8% vs. 68.4%, P=0.058). In the surveillance cohort of 20 AA and 991 NHW, no racial differences in progression to HGD/EAC were observed during a median follow-up of 43 months.

CONCLUSIONS

This study includes the largest number of AA with histologically confirmed BE reported so far. About 46.2% of the AA cohort with BE in our study consisted of women. There was a trend toward a higher prevalence of nondysplastic BE in AA compared with NHW.

Serum insulin-like growth factor (IGF)-I and IGF binding protein-3 in relation to terminal duct lobular unit involution of the normal breast in Caucasian and African American women: The Susan G. Komen Tissue Bank

Lesser degrees of terminal duct lobular unit (TDLU) involution, as reflected by higher numbers of TDLUs and acini/TDLU, are associated with elevated breast cancer risk. In rodent models, the insulin-like growth factor (IGF) system regulates involution of the mammary gland. We examined associations of circulating IGF measures with TDLU involution in normal breast tissues among women without precancerous lesions. Among 715 Caucasian and 283 African American (AA) women who donated normal breast tissue samples to the Komen Tissue Bank between 2009 and 2012 (75% premenopausal), serum concentrations of IGF-I and binding protein (IGFBP)-3 were quantified using enzyme-linked immunosorbent assay. Hematoxilyn and eosin-stained tissue sections were assessed for numbers of TDLUs ("TDLU count"). Zero-inflated Poisson regression models with a robust variance estimator were used to estimate relative risks (RRs) for association of IGF measures (tertiles) with TDLU count by race and menopausal status, adjusting for potential confounders. AA (vs. Caucasian) women had higher age-adjusted mean levels of serum IGF-I (137 vs. 131 ng/mL, p = 0.07) and lower levels of IGFBP-3 (4165 vs. 4684 ng/mL, p < 0.0001). Postmenopausal IGFBP-3 was inversely associated with TDLU count among AA (RR_T3vs.T1  = 0.49, 95% CI = 0.28-0.84, p-trend = 0.04) and Caucasian (RR_T3vs.T1 =0.64, 95% CI = 0.42-0.98, p-trend = 0.04) women. In premenopausal women, higher IGF-I:IGFBP-3 ratios were associated with higher TDLU count in Caucasian (RR_T3vs.T1 =1.33, 95% CI = 1.02-1.75, p-trend = 0.04), but not in AA (RR_T3vs.T1 =0.65, 95% CI = 0.42-1.00, p-trend = 0.05), women. Our data suggest a role of the IGF system, particularly IGFBP-3, in TDLU involution of the normal breast, a breast cancer risk factor, among Caucasian and AA women.

Adiponectin, in contrast to leptin, is not associated with body mass index, waist circumference and HOMA-IR in subjects of a west-African population

Factors associated with plasma levels of adiponectin and leptin were studied in adult subjects without diabetes from Cotonou in Benin (West-Africa). Seventy (70) men and 45 women were included in the study. Anthropometric variables were measured and a venous blood sample was drawn from each subject, after an overnight fasting period, for measurement of plasma glucose, insulin, leptin, and adiponectin levels. HOMA-IR was determined to assess insulin resistance. Adiponectin and leptin levels were higher in women than in men (with adiponectin 18.48 ± 12.77 vs.7.8 ± 10.39 μg/mL, P < 0.0001, and leptin 30.77 ± 19.16 vs. 8.66 ± 8.24 ng/mL, P < 0.0001). Fasting insulin level and HOMA-IR were also higher in the females. Hyperleptinemia was observed in 66,96% of subjects and hypoadiponectinemia was present in 44.35% of subjects. In both men and women, leptin correlated with age (r = 0.2; P = 0.02), BMI (r = 0.572; P < 0.0001), waist circumference (r = 0.534; P < 0.0001), fasting insulin (r = 0.461; P < 0.001), and HOMA-IR (r = 0.430; P < 0.0001). No significant correlation was observed for adiponectin levels with these variables. Only in women, adiponectin was inversely correlated with fasting glucose (r = -0.423; P < 0.004). These data confirm previous descriptions of leptin but suggest that variations in factors determining serum adiponectin levels observed between ethnicities could also been seen between populations from the same ethnicity.

Genetic Markers for Coronary Artery Disease

Coronary artery disease (CAD) and myocardial infarction (MI) are recognized as leading causes of mortality in developed countries. Although typically associated with behavioral risk factors, such as smoking, sedentary lifestyle, and poor dietary habits, such vascular phenotypes have also long been recognized as being related to genetic background. We review the currently available data concerning genetic markers for CAD in English and non-English articles with English abstracts published between 2003 and 2018. As genetic testing is increasingly available, it may be possible to identify adequate genetic markers representing the risk profile and to use them in a clinical setting.

The association between high-sensitivity C-reactive protein and metabolic risk factors in black and white South African women: a cross-sectional study

Background

High-sensitivity C-reactive protein (hsCRP) is associated with metabolic risk, however it is unclear whether the relationship is confounded by racial/ethnic differences in socioeconomic status (SES), lifestyle factors or central adiposity. The aims of the study was, (1) to investigate whether hsCRP levels differ by race/ethnicity; (2) to examine the race/ethnic-specific associations between hsCRP, HOMA-IR and serum lipids [total cholesterol (TC), triglycerides (TG), high-density lipoproteins (HDL-C) and low-density lipoproteins (LDL-C)]; and (3) to determine whether race/ethnic-specific associations are explained by SES, lifestyle factors or waist circumference (WC).

Methods

The convenience sample comprised 195 black and 153 white apparently health women, aged 18-45 years. SES (education, assets and housing density) and lifestyle factors (alcohol use, physical activity and contraceptive use) were collected by questionnaire. Weight, height and WC were measured, and fasting blood samples collected for hsCRP, glucose, insulin, and lipids.

Results

Black women had higher age- and BMI-adjusted hsCRP levels than white women (p = 0.047). hsCRP was associated with HOMA-IR (p < 0.001), TG (p < 0.001), TC (p < 0.05), HDL-C (p < 0.05), and LDL-C (p < 0.05), independent of age and race/ethnicity. The association between hsCRP and lipids differed by race/ethnicity, such that hsCRP was positively associated with TG and LDL-C in white women, and inversely associated with HDL-C in black women. Higher hsCRP was also associated with higher TC in white women and lower TC in black women. Furthermore, when adjusting for SES and lifestyle factors, the associations between hsCRP, and TC and TG, remained, however the associations between hsCRP, and HDL-C and LDL-C, were no longer significant.

Conclusion

Although circulating hsCRP may identify individuals at increased metabolic risk, the heterogeneity in these associations between racial/ethnic groups highlights the need for prospective studies investigating the role of hsCRP for risk prediction in different populations.

Clinical and Economic Burden of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease with an increasing global prevalence associated with tremendous clinical, economic, and health-related quality-of-life burden. Clinically, NAFLD is considered the liver manifestation of metabolic syndrome. However, diagnosing NAFLD presents significant challenges due to the limited noninvasive and accurate diagnostic tools available to not only accurately diagnose nonalcoholic steatohepatitis but also to stage hepatic fibrosis, the major predictor of long-term outcomes, including mortality.

High-molecular weight adiponectin/HOMA-IR ratio as a biomarker of metabolic syndrome in urban multiethnic Brazilian subjects

Metabolic syndrome (MetS) has an important epidemiological relevance due to its increasing prevalence and association with type 2 diabetes and cardiovascular disease. Insulin resistance is a core feature of the MetS. HOMA-IR is a robust clinical and epidemiological marker of MetS. Adiponectin is an adipokine with insulin-sensitizing and anti-inflammatory functions; its levels decrease as number of components of MetS increases. High-molecular weight adiponectin (HMWA) is the multimer responsible for the relationship of adiponectin with insulin sensitivity. HOMA-IR and HMWA are suitable candidates for MetS biomarkers. The ratio of adiponectin to HOMA-IR has been validated as a powerful index of MetS and considered a better marker of its presence, than either HOMA-IR or adiponectin alone, in selected homogeneous populations. We compared the strength of association between HMWA, HOMA-IR and HMWA/HOMA-IR ratio with MetS and its key components. Our data have shown that the median (25^th, 75^th percentile) of HMWA/HOMA-IR ratio was lower in subjects with MetS [0.51 (0.33, 1.31)] as compared to those without it [2.19 (1.13, 4.71)]. The correlation coefficient (r) was significantly higher for HMWA/HOMA-IR ratio as compared to HMWA for waist circumference (-0.65; -0.40, respectively); mean blood pressure (-0.27; -0.14, respectively); fasting glucose (-0.38; -0.19, respectively); HDL-cholesterol (0.44; 0.40, respectively); and triglycerides (-0.35; -0.18, respectively). In a multivariable logistic regression analysis, the HMWA/HOMA-IR ratio was a sensitive predictor for MetS, being the only marker that was significantly associated with each and all the individual components of the syndrome. These results expand on previous studies in that we used the active circulating form of adiponectin, i.e. HMWA, and represent a typical Brazilian cohort characterized by intense interethnic admixture. Thus, the HMWA/HOMA-IR ratio is a minimally invasive biomarker for MetS that could be clinically useful in prognosing patient outcome.

Urea-induced ROS accelerate senescence in endothelial progenitor cells

BACKGROUND AND AIMS

The pathogenic events responsible for the reduction of endothelial progenitor cell (EPC) number and function seen in patients with chronic renal failure (CRF) are poorly understood. Here we investigate the hypothesis that increased concentrations of urea associated with CRF increase ROS production directly in EPCs, causing abnormalities associated with coronary artery disease risk.

METHODS

Human EPCs were isolated from peripheral blood mononuclear cells of healthy donors and cultured in the presence or absence of 20 mmol/L urea.

RESULTS

Urea at concentrations seen in CRF induced ROS production in cultured EPCs. Urea-induced ROS reduced the number of endothelial cell colony forming units, uptake and binding of Dil-Ac-LDL and lectin-1, and the ability to differentiate into CD31- and vascular endothelial growth factor receptor 2-positive cells. Moreover, urea-induced ROS generation accelerated the onset of EPC senescence, leading to a senescence-associated secretory phenotype (SASP). Normalization of mitochondrial ROS production prevented each of these effects of urea.

CONCLUSIONS

These data suggest that urea itself causes both reduced EPC number and increased EPC dysfunction, thereby contributing to the pathogenesis of cardiovascular disease in CRF patients.

Endometrial cancer associated biomarkers in bariatric surgery candidates: exploration of racial differences

BACKGROUND

Obesity is the main risk factor for endometrial cancer (EC), the most common gynecologic malignancy in the United States. A number of potential risk biomarkers have been associated with EC development, including altered proinflammatory cytokines, chemokines, and adipokines.

OBJECTIVES

The overarching aim of this research is to investigate racial differences in the expression of EC-associated biomarkers among bariatric surgery candidates.

SETTING

Tertiary academic medical center METHODS: Blood samples were collected from 175 women aged 18 to 72 (mean age: 42.93; standard deviation 11.66), before bariatric surgery. Levels of biomarkers associated with obesity and EC risk were measured using xMAP immunoassays. Wilcoxon rank sum and Fisher's exact tests were utilized to compare biomarker and demographic variables between African American and European American women. Linear regression models, adjusted for menopause status and diabetes, were utilized to identify factors associated with biomarker levels.

RESULTS

When the biomarker levels were compared by race, insulin-like growth factor-binding protein 1 and adiponectin were significantly lower in African American women (P<.05), whereas estradiol was significantly higher in African American women (P<.05). Linear regression models found that race significantly predicted insulin-like growth factor binding protein 1, adiponectin, resistin, and interleukin-1 receptor alpha expression levels, menopause status and diabetes status were significantly associated with adiponectin and leptin levels, whereas body mass index was significantly associated with leptin, adiponectin, interleukin-1 receptor alpha, and interleukin-6 levels.

CONCLUSION

As one of the first efforts to explore racial differences in EC-associated biomarkers in a cohort of women with severe obesity, this study found several significant differences that should be further explored in large-scale studies.

Relationship of adiponectin and leptin with autoimmunity in children with new-onset type 1 diabetes: a pilot study

AIM

To explore racial differences in adiponectin, and leptin and their relationship with islet autoimmunity in children with new-onset type 1 diabetes (T1D).

METHODS

Medical records were reviewed from a cohort of new-onset clinically diagnosed T1D subjects matched by race, age, gender, and year of diagnosis. Sera were available for 156 subjects (77 African American (AA), 79 Caucasian (C), 48% male, age of 11.1 ± 3.8 yr) and assayed for adiponectin and leptin prior to (D0), 3, 5 d, and 2-4 months (M3) after insulin therapy and islet autoantibodies to GAD, IA2, insulin, and ICA were measured at onset.

RESULTS

Adiponectin levels increased significantly following insulin therapy by day 5 (D5) (D0: 13.7 ± 7.2 vs. D5: 21.3 ± 9.9 µg/mL, p < 0.0001), but no further significant increase from D5 to M3. At DO, AA had lower adiponectin levels (10.5 vs. 15.7 µg/mL, p = 0.01), were more often overweight than C (55 vs. 18%, BMI ≥ 85th‰) and fewer had positive autoantibodies (72 vs. 87%, p = 0.05). Racial differences in adipocytokines disappeared after adjustment for BMI. At M3, subjects with more number of positive autoantibodies had higher adiponectin levels (p = 0.043) and adiponectin/leptin ratio (ALR) (p = 0.01), and lower leptin levels (p = 0.016).

CONCLUSION

Adiponectin levels increased acutely with insulin therapy. Significantly lower adiponectin levels in AA were related to greater adiposity and not race. These pilot data showing those with the fewest autoantibodies had the lowest adiponectin levels, supporting the concept that insulin-resistant subjects may present with clinical T1D at earlier stages of β-cell damage.

The role of adipokines in ischemic stroke risk stratification

Background

Adiponectin, leptin, and resistin are the most well-studied adipokines and play important roles in the regulation of glucose metabolism, subclinical inflammation, and cardiovascular homeostasis. Accordingly, measurement of adipokine levels might be useful in cardiovascular risk stratification. Moreover, the study of single-nucleotide polymorphisms of genes that encode these adipokines might also represent a valuable predictive tool in cardiovascular disease prevention strategies.

Aims

To summarize the biologic role of the adipokines adiponectin, leptin, and resistin and the prognostic value of their serum levels regarding the occurrence and outcome of ischemic stroke. We also discuss the relationship of single-nucleotide polymorphisms of the adiponectin, leptin genes, and the −420C > G polymorphism of resistin gene with stroke risk.

Summary of review

Several studies in the general population evaluated the association between these adipokines and stroke risk, yielding conflicting results. There are more limited data regarding the effect of these adipokines on stroke severity and outcome. A small number of studies also assessed the predictive role of single-nucleotide polymorphisms of the adiponectin, leptin, and resistin genes regarding stroke risk, but the findings were also controversial.

Conclusions

It is unclear whether adiponectin, leptin, and resistin levels or the single-nucleotide polymorphisms of their encoding genes are independently associated with stroke risk. However, given the role of these adipokines in the pathogenesis of atherosclerosis, larger prospective studies, both in the general population and in patients with a history of stroke, are needed to determine whether the measurement of serum levels of these adipokines or the evaluation of single-nucleotide polymorphisms in their encoding genes could improve stroke risk prediction. If this relationship is proven, therapeutic interventions targeting adipokine levels might represent a novel approach to reduce stroke-related mortality and disability.

Association of adiponectin and metabolic syndrome in adolescents: the caspian- III study

Background

This study aimed to investigate the associations between metabolic syndrome (Mets) and adiponectin concentrations in Iranian adolescents.

Methods

This study was conducted as a sub-study of a national school- based surveillance program in 10–18 year- old students from 27 provinces in Iran. Plasma adiponectin was measured in 180 randomly selected participants. Metabolic syndrome (Mets) was defined based on the Adult Treatment Panel III (ATP- III) criteria modified for the pediatric age group. Multiple logistic regression analyses were used to evaluate the association between adiponectin and cardiometabolic risk factors.

Results

The median of adiponectin concentrations was significantly lower among participants with Mets [2.95 μg/ml (interquartile range 2.72–3.30)] compared with subjects without Mets [4.55 μg/ml (interquartile range 3.02–5.75)]. Adiponectin showed significant negative association with higher number of Mets components (P- trend < 0.05). Significant correlations were observed between adiponectin concentrations and metabolic parameters, except blood pressure.

Significant inverse association existed between adiponectin levels and presence of Mets (OR, 0.21; 95%CI: 0.10–0.45; p < 0.001). In multivariate models, this association remained significant after adjustment for other risk factors (OR, 0.18; 95%CI: 0.07–0.47; p < 0.001.

Conclusions

Adiponectinhas inverse association with cardiometabolic parameters in Iranian adolescents, and it is a determinant of Mets independent of other risk factors. These findings can be used in comparison with other ethnic groups. Further longitudinal studies are necessary to assess the clinical impact of such inverse association.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Gender-specific associations between ADIPOQ gene polymorphisms and adiponectin levels and obesity in the Jackson Heart Study cohort

BACKGROUND

Despite the important role of adiponectin in regulating general metabolic homeostasis, analysis of genetic determinants of adiponectin and the related cardio-metabolic traits in African American population has been limited and inconsistent. Considering the high genetic admixture of African Americans and thus the important population stratification that may confound the genetic-trait associations, the objective of this work was to perform a comprehensive analysis of the associations between ADIPOQ variants and adiponectin levels and obesity phenotypes in a large African American population from the Jackson Heart Study (JHS) cohort.

METHODS

Genotype data was available for 2968 JHS participants (1131men; 1837women). Single Nucleotide Polymorphisms (SNPs) were selected by a Tag-SNP Approach and literature review. The genotype imputation was performed using IMPUTE2 software and reference phased data from the 1000G project. PLINK software was used for the genetic analysis. Plasma specimens were analyzed by ELISA for adiponectin levels. All analyses were controlled for population stratification assessed by Individual Proportions of European Ancestry (PEA) estimates calculated in HAPMIX using ancestry informative markers (AIMs).

RESULTS

We found a gender-dependent association of some ADIPOQ variants and adiponectin levels. In women four of the studied polymorphisms (rs6444174, rs16861205, rs1403697, rs7641507) were associated with adiponectin levels after Bonferroni correction and controlling for the percentage of PEA, age, annual household income and smoking. These results were consistent with the haplotype analysis. The association between the rs12495941 variant and obesity is modulated by the PEA, so that the relationship between the G allele and a higher incidence of obesity was present in those individuals within the lower PEA group. In addition we found an effect modification of obesity on the association between the ADIPOQ rs6444174 SNP and BMI so that the presence of the T allele was negatively and significantly associated with BMI only in participants with a normal weight.

CONCLUSIONS

In this large African American cohort, ADIPOQ variants were associated with adiponectin levels in a gender-dependent manner and the relationship of some of these variants with obesity and BMI was modulated by the PEA and obesity status respectively. This suggests that the effects of these polymorphisms on adiponectin and obesity phenotypes are subject to a strong interaction with genetic and environmental factors in African American population.

Obesity adversely affects serum anti-müllerian hormone (AMH) levels in Caucasian women

OBJECTIVE

Previous studies regarding the effect of obesity on serum anti-müllerian hormone (AMH) levels have been conflicting. Our aim was to determine the effect of obesity on serum AMH levels among women from different racial backgrounds.

METHODS

The medical records of 350 women (159 Caucasian, 99 African-American, 58 Hispanic, 34 Asian with ages 16-46) evaluated for infertility at an academic-affiliated center and who had AMH levels measured as part of their evaluation were reviewed. Age, AMH, body mass index (BMI), self-reported race, etiology of infertility, smoking history, maximum serum early follicular follicle-stimulating hormone (FSH) levels, antral follicle count (AFC), and history of ovarian surgery, chemotherapy, or radiotherapy were recorded.

RESULTS

Age correlated negatively with AMH and antral follicle count across all races (p < 0.05). After adjusting for age, polycystic ovary syndrome diagnosis, and smoking, elevated BMI had a negative correlation with AMH in Caucasian women (β = 0.17, p = 0.01) but not in African-American, Hispanic, or Asian women.

CONCLUSION

Elevated BMI correlates negatively with AMH in Caucasian women but not in African-American, Hispanic, or Asian women. Additional studies are needed to elucidate further the effect of race on the interaction between obesity and ovarian reserve.

The Interplay Between Sex, Ethnicity, and Adipose Tissue Characteristics

The obesity epidemic in the USA affects disproportionately women and the ethnic minorities. On the other hand, female sex is traditionally associated with a favorable fat distribution preferentially in the subcutaneous depots of the lower body and with improved endocrine and metabolic function of the adipose tissue. However, these data are derived from predominantly non-Hispanic white populations. This review discusses fat distribution patterns in women of diverse ethnic backgrounds, together with data on the release of adipokines from adipose tissue in these populations. Very little information is available on how the metabolic function of the adipocyte differs depending on ethnicity. Thus, it becomes clear that future clinical and translational research should explicitly discuss and take into account the sex and ethnic background of the populations studied.

Racial/Ethnic Differences in Insulin Resistance and Beta Cell Function: Relationship to Racial Disparities in Type 2 Diabetes among African Americans versus Caucasians

Both biological and sociocultural factors have been implicated in the well-documented racial disparity in incidence and prevalence of type 2 diabetes (T2D) between African Americans (AA) and non-Hispanic whites (NHW). This review examines the extent to which biological differences in glucose metabolism, specifically insulin resistance and beta cell function (BCF), contribute to this disparity. The majority of available data suggests that AA are more insulin resistant and have upregulated BCF compared to NHW. Increasing evidence implicates high insulin secretion as a cause rather than consequence of T2D; therefore, upregulated BCF in AA may specifically confer increased risk of T2D in this cohort. Racial disparities in the metabolic characteristics of T2D have direct implications for the treatment and health consequences of this disease; therefore, future research is needed to determine whether strategies to reduce insulin secretion in AA may prevent or delay T2D and lessen racial health disparities.

Leptin Reference Values and Cutoffs for Identifying Cardiometabolic Abnormalities in the Spanish Population

INTRODUCTION AND OBJECTIVES

Estimate leptin reference values and calculate leptinemia cutoff values for identifying cardiometabolic abnormalities in Spain.

METHODS

Cross-sectional study carried out between 2008 and 2010 in 11 540 individuals representing the Spanish population aged ≥ 18 years. Data were obtained by standardized physical examination and analyses were performed at a central laboratory. Leptinemia was measured using ELISA. Cardiometabolic abnormality was defined as the presence of at least two of the following: high blood pressure, high triglycerides, reduced high density lipoprotein cholesterol, high insulin resistance values, and elevated C-reactive protein and glucose.

RESULTS

Leptin values were higher in women than men (geometric mean, 21.9 and 6.6 ng/mL; P<.001). The median [interquartile range] was 24.5 [14.1-37.0] ng/mL in women, and 7.2 [3.3-14.3] ng/mL in men. In the multivariate analysis, leptin was significantly associated with anthropometric measures, insulin, and C-reactive protein, and inversely associated with age, smoking, and physical activity in women (r(2)=0.53; P<.001) and in men (r(2)=0.61; P<.001). The leptin values that identified cardiometabolic abnormality were 23.75 ng/mL in women (area under the curve, 0.722; sensitivity, 72.3%; specificity, 58.7%) and 6.45 ng/mL in men (area under the curve, 0.716; sensitivity, 71.4%; specificity, 60.2%).

CONCLUSIONS

These results facilitate the interpretation of leptin values in clinical and population studies. Leptin has moderate sensitivity and specificity for identifying cardiometabolic abnormalities.

Ethnic differences in bone health

There are differences in bone health between ethnic groups in both men and in women. Variations in body size and composition are likely to contribute to reported differences. Most studies report ethnic differences in areal bone mineral density (aBMD), which do not consistently parallel ethnic patterns in fracture rates. This suggests that other parameters beside aBMD should be considered when determining fracture risk between and within populations, including other aspects of bone strength: bone structure and microarchitecture, as well as muscle strength (mass, force generation, anatomy) and fat mass. We review what is known about differences in bone-densitometry-derived outcomes between ethnic groups and the extent to which they account for the differences in fracture risk. Studies are included that were published primarily between 1994 and 2014. A "one size fits all approach" should definitely not be used to understand better ethnic differences in fracture risk.

Adipokines: a link between obesity and dementia?

Being overweight or obese, as measured with body-mass index or central adiposity (waist circumference), and the trajectory of body-mass index over the life course have been associated with brain atrophy, white matter changes, disturbances of blood-brain barrier integrity, and risk of all-cause late-onset dementia and Alzheimer's disease. This observation leads us to question what it is about body-mass index that is associated with health of the brain and dementia risk. If high body-mass index and central adiposity represent an increase in adipose tissue, then the endocrine function of adipose tissue, mediated by adipose tissue hormones and adipokines, could be a clue to mechanisms that underlie the association with dementia and Alzheimer's disease. Hundreds of adipokines have been identified, creating a complexity that is a challenge to simplify. Nonetheless, adipokines are being investigated in association with clinical dementia outcomes, and with imaging-based measures of brain volume, structure, and function in human beings and in preclinical models of clinical dementia.

Serum adiposity-induced biomarkers in obese and lean children with recently diagnosed autoimmune type 1 diabetes

BACKGROUND/OBJECTIVE

Obesity increases the risk of cardiovascular disease and diabetic complications in type 1 diabetes. Adipokines, which regulate obesity-induced inflammation, may contribute to this association. We compared serum adipokines and inflammatory cytokines in obese and lean children with new-onset autoimmune type 1 diabetes.

SUBJECTS AND METHODS

We prospectively studied 32 lean and 18 obese children (age range: 2-18 yr) with new-onset autoimmune type 1 diabetes and followed them for up to 2 yr. Serum adipokines [leptin, total and high molecular weight (HMW) adiponectin, omentin, resistin, chemerin, visfatin], cytokines [interferon (IFN)-gamma, interleukin (IL)-10, IL-12, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha] and C-reactive protein (CRP) were measured at a median of 7 wk after diagnosis (range: 3-16 wk).

RESULTS

Lean children were 71.9% non-Hispanic White, 21.9% Hispanic, and 6.3% African-American, compared with 27.8, 55.6, and 16.7%, respectively, for obese children (p = 0.01). Compared with lean children, obese children had significantly higher serum leptin, visfatin, chemerin, TNF-alpha and CRP, and lower total adiponectin and omentin after adjustment for race/ethnicity and Tanner stage. African-American race was independently associated with higher leptin among youth ≥10 yr (p = 0.007). Leptin levels at onset positively correlated with hemoglobin A1c after 1-2 yr (p = 0.0001) independently of body mass index, race/ethnicity, and diabetes duration. Higher TNF-alpha was associated with obesity and female gender, after adjustment for race/ethnicity (p = 0.0003).

CONCLUSION

Obese children with new-onset autoimmune type 1 diabetes have a proinflammatory profile of circulating adipokines and cytokines that may contribute to the development of cardiovascular disease and diabetic complications.